Biocompatible Polymer System for Extended Drug Release

Abstract

A self-orienting biocompatible polymer system incorporating a hydrophilic surface and a hydrophobic core are disclosed. The hydrophilic surface aids in biocompatibility while the hydrophobic core allows the polymer system to accommodate a hydrophobic drug. Medical devices coated with the polymer system are also disclosed.

1 . A polymer system for coating medical devices comprising:
 a polymer blend, wherein said polymer blend forms a self-orienting polymer coating having an outer surface, and wherein said polymer coating has hydrophilic groups oriented towards said outer surface.   
   
   
       2 . The polymer system of  claim 1  wherein said polymer blend comprises at least one of a homopolymer, a copolymer or a terpolymer. 
   
   
       3 . The polymer system of  claim 1  wherein said self-orienting polymer coating is capable of controlled release of a hydrophobic drug. 
   
   
       4 . The polymer system of  claim 3  wherein said self-orienting polymer coating is biocompatible. 
   
   
       5 . The polymer system according to  claim 3  wherein said hydrophobic drug is selected from the group consisting of anti-proliferatives, estrogens, chaperone inhibitors, protease inhibitors, protein-tyrosine kinase inhibitors, leptomycin B, peroxisome proliferator-activated receptor gamma ligands (PPARγ), hypothemycin, nitric oxide, bisphosphonates, epidermal growth factor inhibitors, antibodies, proteasome inhibitors, antibiotics, anti-inflammatories, anti-sense nucleotides and transforming nucleic acids. 
   
   
       6 . The medical device according to  claim 3  wherein said drug comprises at least one compound selected from the group consisting of sirolimus (rapamycin) and its analogs, tacrolimus (FK506), everolimus (certican), temsirolimus (CCI-779), zotarolimus (ABT-578), paclitaxel and its analogs. 
   
   
       7 . The polymer system of  claim 1  wherein said outer surface has a water contact angle of <95°. 
   
   
       8 . The polymer system according to  claim 2  wherein said copolymer comprises alkyl methacrylate monomers, vinyl acetate monomers or combinations thereof. 
   
   
       9 . The polymer system according to  claim 2  wherein said terpolymer comprises alkyl methacrylate monomers, vinyl pyrrolidone monomers, vinyl acetate monomers or combinations thereof. 
   
   
       10 . The polymer system according to  claim 2  wherein said homopolymer comprises vinyl pyrrolidone monomers. 
   
   
       11 . The polymer system according to  claim 1 , wherein said coating's outer surface has a Hilderbrand solubility parameter of about 15 to about 20. 
   
   
       12 . The polymer system according to  claim 2  comprising a ratio of terpolymer to copolymer to homopolymer, wherein said ratio is from about 40:40:20 to about 88:10:2. 
   
   
       13 . A biocompatible medical device comprising:
 a substrate comprising a coating on a surface;   wherein said coating comprises a self-orienting polymer system,   further wherein said polymer system comprises an outer surface; and   further wherein said polymer system has hydrophilic groups oriented towards said outer surface.   
   
   
       14 . The medical device according to  claim 13  wherein said polymer system comprises a at least one of a homopolymer, a copolymer, or a terpolymer. 
   
   
       15 . The medical device according to  claim 13  wherein said medical device is implantable and is selected from the group consisting of heart valves, stents, pacemaker leads and combinations thereof. 
   
   
       16 . The medical device according to  claim 13  wherein said self-orienting polymer coating is capable of controlled release of a hydrophobic drug. 
   
   
       17 . The medical device according to  claim 16  wherein said hydrophobic drug comprises at least one compound selected from the group consisting of sirolimus (rapamycin) and its analogs, tacrolimus (FK506), everolimus (certican), temsirolimus (CCI-779), zotarolimus (ABT-578), paclitaxel and its analogs. 
   
   
       18 . The medical device according to  claim 14  wherein said copolymer comprises alkyl methacrylate monomers, vinyl acetate monomers, or combinations thereof. 
   
   
       19 . The medical device according to  claim 14  wherein said terpolymer comprises alkyll methacrylate monomers, vinyl pyrrolidone monomers, vinyl acetate monomers, or combinations thereof. 
   
   
       20 . The medical device according to  claim 14  wherein said homopolymer comprises vinyl pyrrolidone monomers. 
   
   
       21 . The medical device according to  claim 13  wherein said outer surface has a water contact angle of <95°. 
   
   
       22 . The medical device according to  claim 13 , wherein said outer surface has a Hilderbrand solubility parameter of about 15 to about 20. 
   
   
       23 . The polymer system according to  claim 13  comprising a ratio of terpolymer to copolymer to homopolymer, wherein said ratio is from about 40:40:20 to about 88:10:2. 
   
   
       24 . A biocompatible implantable stent comprising:
 a self-orienting polymer system coating comprising at least one of polyvinylpyrrolidone, alkyl methacrylate, vinyl acetate, and vinylpyrrolidone;   wherein said polymer system further comprises a hydrophilic surface and a hydrophobic core;   wherein said hydrophobic core comprises a hydrophobic drug and can provide controlled release;   wherein said drug comprises zotarolimus.